Safety locking apparatus for elevators



D. A. SANFQRD I SAFETY LOCKING APPARATUS FOR ELEVATORS Original Filed Dec. 10 19230 3 Sheets-Sheec l @UNA fiAR-IFUBD IIVVENTOR ATTORNEYS 1 5ZMAM5 Nave 4% 1924.,

D. A. SANFORD SAFETY LOCKING APPARATUS FOR ELEVATORS 3 Sheets-Sheet Original Filed Dec. 10, 1920 wally WITNESSES v ATTORNEYS Nmm 4 9 11924 I D. A. SANFOFQB SAFETY LOCKING APPARATUS FOR ELEVATORS Original Filed Dec. 10 1920 3 Sheets-Sheet 5 DG/V An WITNESSES I/W E/VTOR aw/mi 4 TTORNEYS Patented Nov. 4, 1924.

UNITED STATES PATENT OFFICE.

DON ALONZO SANFORD, OF WASHINGTON, DISTRICT OF COLUMBIA; GBETA L. SAN- FORD ADMINISTRATRIX OF SAID DON ALONZO SANFORD, DECEASED.

SAFETY LOCKING APPARATUS FOR ELEVATORS.

Application filed December 10, 1920, Serial 1T0. 429,628. Renewed January 26, 1924.

Apparatus for Elevators, of which the fol-- lowing is a specification.

My invention relates to safety locking apparatus for elevators, and the purpose of my invention is the provision of a safety looking apparatus which operates to normally lock the hatch-way doors and to unlock the doors so that they can be opened only when the elevator car is stopped at or within a limited distance of the floor landings; my invention including a novel form of lock which is responsive to magnetic lines of .force emanating from the carcarried electro-magnet to move the lock to releasing position, and a switch controlled circuit for the magnet which is operable by the controlling lever of the car to complete the magnet circuit during the movement of the controlling lever from the up, or down position to the neutral or stop position, so that when the car is approaching a landing in either direction, the normal operation of the controlling lever will effect an energization of the magnet for a period suflicient to permit the operator to open the door where.- upon the magnet is again de-energized so as to avoid any waste of current. Furthermore, my invention provides means operable by the lock for disrupting the car power circuit when the lock is in released position, so that with the hatch-way door open,'it is im ossible to start the car.

will describe one form of safety locking apparatus embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings:

Figure 1 is a view showing diagrammatically a conventional, form of elevator car and hatch-way door, having applied thereto one form of safety locking apparatus embodying my invention.

Figure 2 is a top plan view of the look and magnet embodied in the apparatus shown in Figure 1, with the lock casing shown in section.

Figure 3 is a View showing in front elevation the 100K shown in Figure 2 with the lock casing in section and the locking lever in disengaging position with respect to the door-carried locking arm.

Figure 4 is a longitudinal sectional view of tgie lock taken on the line 4-4 of Figure Figure 5 is a view similar to Figure 3 showing the lock in rear elevation with a. portion of the lock casing broken away.

Figure 6 is a vertical sectional view of the lock shown in the preceding views taken on the line 6 6 of Figure 3, and showing one of the poles of the magnet in operative relation with respect to the lock.

Figure 7 is an enlarged detail perspective View of the locking lever shown in the preceding views.

Similar reference characters refer to similar parts in each of the several views.

Referring to the drawings in detail, my invention in its present embodiment includes a lock generally indicated at L and comprising a casing 15 preferably formed contour shown and formed of magnetic material. The releasing member 18 is designed to control the movement in one direction of a locking lever 19 which, as shown in F igure 3 is fulcrumed adjacent its lower end upon a screw 20 fixed within the casing 15 at a point directly above a slot 21 formed in the lower wall of the casing so that the lower end of the locking lever at all times projects through the slot and exteriorly of the casing. As shown in Figure 7, the locking lever 19 is formed at its lower end with anoperating lip 19 and a locking lip 19", thelatter of which is spaced from and disposed at an angle to the operatlng lip.

The upper end of the lever 19 is formed on its forward side with a projection 19 which is adapted to co-act with a similar projection 18 fixed on the inner side of the releasing member 18. As shown in Figure 2, the projections 19 and 18 are formed with surfaces which are inclined in opposite directions to permit of the movement of the projection 19 in one direction over the projection 18, but to lock the same when moving in the oppositedirection. Intermediate the ends of the lever 19, oppositely inclined surfaces 19 and 19 are formed which are adapted to co-act with a leaf spring 22 for maintaining the locking lever in either of its extreme positions against accidental displacement. As shown in Figure 2, the spring 22 is secured at one end to the casing 15, and is bent longitudinally to provide oppositely inclined surfaces which engage with surfaces 19 and 19 in the manner shown in Figure 4. A stop 23 is sustained within the casing 15 for defining one extreme position of the locking lever 19, the other extreme position of the lever being defined by a switch designated generally at S and which in the present instance comprises .a block 24 of insulating material secured within the casing 15 by screws 25 and supporting stationary contact arms 26 which are adapted to be bridged by a contact finger 27 secured to and insulated from the locking lever 19. v

A conventional form of elevator car C is shown in Figure 1 in discharging position with respect to the landing D. A sliding door E of conventional form controls the hatch-way and is provided at its upper edge with a longitudinally extending bar 28 to which is secured a locking finger 29. The lock L is suitably sustained in overlying relation with respect to the door E and in such position that the lower end of the locking lever 19 is disposed in the path of movement of the locking finger 29 as the door E is moved to open or closed position. In the open position of the door E, the locking finger 29 is disengaged from the locking lever, with the latter occupying the extreme position shown in solid lines in Figure 3 which is the releasin position. When the door E ismoved to closed position, the locking finger 29 engages the operating lip 19 so as to move the locking lever 19 to the other extreme position as shown in dash lines in Figure 3. This other extreme position is termed the locking position of the lever 19, and in this position the contact finger 27 engages the contact arms 26 to close the switch S. It will be understood that in the releasing position of the locking lever, the inclined surface 19 engages the spring 22, while in the locking position of the lever, the surface 19 engages the spring.

As shown in Figure 1, the elevator car C carries an electro-magnet M of conventional form which isso positioned that its pole pieces are disposed in close proximity to the releasing member 18 of the lock L when the car is at or adjacent to the landing D. This electro-magnet M is provided with a circuit which constitutes a branch of the main lighting circuit for the elevator. The magnet circuit is controlled by a switch S mounted in the car C and within or adjacent to the controller box in such manner as to be operated by the controlling lever of the car. The control lever is designated at G and is fulcrumed on the control box designated at B at the point indicated at 30, so that it can be manually swung from the neutral position shown in Figure 1, to the left to engage contact 31, and to the right to engage contact 32. When engaging the contact 31 or 32, the usual circuits for setting into actuation the car actuating mechanism are completed, in such manner as to cause the car to ascend or descend according as the lever engages one contact or the other.

The control lever G is provided with a S includes the contact arm 34 and a stationary, contact 35, the former being bent transversely to provide projections engageable by the lug 33 and spaced apart so that when the lever G is moved in either direction from the neutral position, it will engage one or the other of the projections to efiect a closing of the switch. It is to be particularly noted that the projections and lug co-act in such a manner as to close the switch as the lever is being moved from one extreme position to the neutral position, but that after such lever reaches the neutral position, the lug 33 disengages the contact arm and thus permits the switch to open. This particular arrangement is designed for the purpose of preventing the energization ofthe magnet M when the door E is in open position.

As previously stated, the magnet M is adapted to be disposed in closed proximity to the releasing member 18 of the lock when the elevator car is in discharging position, so that when the magnet is energized. the releasing member 18 will be within the magnetic field of the magnet and'thus subjected to the influence of such magnet. The releasing member 18 is normally urged to a lock-' ing position with respect to the locking lever 19 by springs 18', secured to the member and bearing against the casing. When subjected to the influence of the magnet M, this releasing member is swung in the direction of the magnet and against the action of the spring 18 to move the projection 18 out of the path of movement of the projection 19. This movement of the member 18 effects a release of the lock L, as will be hereinafter described.

Theoperation of the entire apparatus is as follows: With the door E closed, the locking lever 19 occupies the position shown in dashlines in Figure 3, wherein, the looking finger 29 is interposed between the lips 19 and 19'. In this position of th'elocking lever, the projections 19 and 18 are in abutting relat on to each other so that the lever is locked against movement. It will thus be seen that movement of the door E to open position cannot be effected because the locking finger 29 is locked against movement by means of the locking lip 19. When the car C reaches the landing D, approaching from either direction, the controlling lever G being in engagement with either contact 31 or contact 32, said lever is moved from said contact 31 or 32 towards a neutral position until the lug 33 engages one of the projections or humps of the contact arm 34, a slight further movement of the lever depresses the contact arm and brings the end thereof into engagement with contact 35, thus closing the circuit and energizing the magnet M, and moving the armature or releasing member 18 to an unlocking position. The circuit is as follows: from wire 36 through wire 37, contact 35, contact arm 34, wire 38, windings of magnet M, wire 39, to wire 40. The wires 36 and 40 constitute the lighting circuit for the car and as usual, are in the form of flexible cables which extend to the source of current located at some convenient point within the well. With the circuit for the magnet M closed, the magnet is energized thus actuating the member 18 to release the locking lever 19, whereby the operator can slide the door E to open position. During the movement of the door to open position the locking finger 29 strikes the locking lip 19 and thus swings the looking lever to the position shown in solid lines in Figure 3. With the movement of the locking lever to release position, it will be clear that the switch S is opened, this opening of the switch effecting a breaking of the control circuit for the elevator car. As shown in Figure 1, conductors 41 and 42 are connected to the contact arms 26 and constitute one side of the control circuit, the wire ll being connected to the control lever G. With this arrangement, it will be clear that when the switch S is opened, the supply of current to the lever G is discontinued, so that with the locking lever 19 in release position, it is impossible for the elevator car to be started.

When the door is moved to closed position, the locking finger 29 escapes the lip 19 but engages the lip 19*, and thus swings the locking lever 19 to locking position, it being understood that the releasing member 18 through the de-energization of the magnet M has in the meantime returned to normal position so as to move the projection 18 into locking position with respect to the projection 19. As the locking lever reaches the lockingposition, the switch S is closed, thus completing the controlling circuit so that movement of the car can be effected by further manipulation of the control lever G.

It is to be particularly noted that the area of the releasing member 18 is such as to 'be within the influence of the magnet M necessary that the operator stop the car exactly at the landing before the actuation of the lock can be effected. It is to be further noted that the circuit for the magnet M constituting a branch of the ordinary lighting circuit for the car, insures the releasing of the lock should the control circuit be disrupted, as often occurs under actual workingconditions.

Although I have herein shown and described only one form of safety locking apparatus embodying my inventionfit is to be understood that various changes and modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

I claim 1. The combination in a safety locking apparatus for elevator doors, of a hatchway door carrying door-holding means adapted to be engaged by a locking element; an elevator car; an electro-magnet carried by the car; an electric circuit for the electro-magnet adapted to be connected with a suitable source of electrical energy; a switch for controlling the circuit; and a lock comprising a movable door-locking element adapted to engage said door-holding means and normally lock the door, and an element of magnetic material constituting an armature nor- 'mally holding said door-locking element in looking position; said element of magnetic material being movable within limits, and, when actuated by the 'electro-magnet carried by'the car, moving to release the doorlocking element.

2. The subject-matter of claim 1 with the addition of an electric control circuit adapted for connection with an electric motor for operating the car, said circuit being closed by the said door-locking element when the hatchway door is locked and opened when the said door is opened.

3. The subject-matter of claim 1 with the addition of spring means for actuating the said element of magnetic material to hold said door-locking elementin looking position, said element of magnetic material being moved when actuated by the electromagnet against the energy exerted by the spring means.

{1. The subject-matter of claim 1 with the addition of a casing on which the said doorlocking element and said element of magnetic material are movably supported, said two elements being adapted to interlock, for the purpose specified, in one of their relative positions.

5. The subject-matter of claim 1 with the addition of a casing suitably supported adjacent the path of travel of the electro-mag- &

} closed.

6. The subject-matter of claim 1 with the addition of a casing supported adjacent the -path of travel of the electro-magnet on the car, the said door-locking element and the said element of magnetic material being movably supported by the casing; and an electric car control circuit adapted for connection with an electric motor for operating the car, said circuit extending to the said r asing and means in connection with the said door-locking element for opening the circuit when the door is opened and closing thecircuit when the door is closed.

said casing adjacent the path of travel of the electro-magnet on the car being substantially of non-magnetic material.

8. The. combination in a'safety locking apparatus for elevator doors, of a hatchway door carrying door-holding means, an elevator car, an electro-magnet carried by the car, an electric circuit for the electromagnet, a switch in said circuit, a lock having a locking member adapted to engage said door-holding means, and an element of magnetic material normally holding said member in locked position, said element of magnetic material being supported adjacent .the path of the electro-magnet in its travel with the car and movable under the action of the electro-magnet to release the said locking member from its locking position.

9. The combination in a safety locking apparatus for elevator doors, of a hatchway door carrying door-holding means, an elevator car, an electro-magnet carried by the car, an electric circuit for the electro-magnet, a switch in said circuit, a lock including a locking member having lips adapted to be engaged by said door-holding means whereby the locking member may be moved within its limits of travel in either direction, a member of magnetic material movable to lock and release the said locking member, and means for moving the said member of magnetic material so as to normally look said locking member a ainst movement; said member of magnetic material being supported adjacent the path of travel of v the electro-magnet on the car whereby it can be moved to release the said locking member.

10. The combination of an elevator car, an electro-magnet carried by the car, means for energizing said electr c-magnet, a hatchway door carrying holding means, a lock including a locking lever capable of occupying a locking position and a releasing position and located in the path of travel of said door-holding means whereby the levercan be moved to locking and released positions by said door-holding means, and means normally acting to retain the lever in a locked position, the last mentioned means being located adjacent the path of travel of the electro-magnet whereby when the electro-magnet is energized and opposite said means it will be moved and release the locking lever.

11. The combination of an elevator car, a locking lever supported to occupy locking and releasing positions, a hatchway door carrying means movable toengage said lever and move the same to either of its extreme positions, a member of magnetic material normally maintaining the locking lever in looking position, a switch in an electric circuit controlled by said lever and adapted to be closed or opened according as the lever occupies the looking or releasing position, and an electro-magnet carried by the car for moving said member of magnetic. material to release the said locking lever when said electro-magnet in its travel is brought opposite said member of magnetic material.

The combination of an elevator car, an electro-magnet carried by the car, an electric circuit for the electro-magnet, a switch in the circuit, a hatchway door, a locking apparatus for said door comprising a looking member movable to occupy locking and releasing positions, a releasing member of magnetic material located adjacent the path of travel of the electro-magnet carried by the car, said releasing member being movable to occupy locking and releasing positions in respect to the locking member when said member occupies the aforesaid res ective positions, a main electrical circuit for controlling the movements of the car, and controlling means for said main circuit associated with the locking member adapted to close the circuit when the locking position is assumed and open the circuit when the releasing position is assumed.

13. The combination with a locking member, of means on which it is pivoted to rock in one plane, a hatchway door with means to move said member into a locking position, a releasing member pivoted to rock in a plane different from the rocking plane of the locking member and occupy locking and releasing positions in' respect to said locking member and thus correspond to the respec-. tive positions of said member, an elevator car, an electro-magnet carried by the car, and an electrical circuit for the electromagnet; the electro-magnet when energized being adapted to move said releasing member from a locking to a releasing position.

.14. The subject-matter of claim 13 with the addition of a main electrical circuit for controlling the movements of the car and a switch in said circuit controlled by means associated with the locking member.

15. In an apparatus of the character described, the combination of a movable looking member, a hatchway door with means to move the said locking member from locking position to released position, and vice versa, a releasing member of magnetic material co-operating with the locking member, the said releasing member being limited in its movements in opposite directions, an elevator car, an electro-magnet carried by the car, an electrical circuit 'for the electro-magnet, and a switch for the circuit; the said releasing member being located adjacent the path of travel of the electro-magnet and adapted to be moved to a releasing position by the action of the said electro-magnet.

16. In an apparatus for the purpose set forth, the combination of a movable locking member, means for limiting its movements in opposite directions, a hatchway door adapted to be engaged and locked by said movable locking member when in one of its positions, a movable releasing member 01 magnetic material co-operating with the said locking member, means for limiting the movements of the said releasing member in opposite directions, an elevator car, an electro-magnet carried bv the car, an electrical circuit for the electro-magnet, and a switch for the circuit; the said releasin member being located adjacent the path of-travel of the electro-magnet and movable under the influence of said electro-magnet to release the said movable locking member so it can move from its locking to its releasing position relative to the door.

17. The-subject-matter of claim 16 with the addition of spring means to normally hold the releasing member so as to maintain the locking member in its locked position.

18. The subject-matter of claim 16 with the addition of a main electrical circuit for controlling the movements of the car, and a switch in said circuit controlled by the said movable locking member.

19. The combination with an elevator car carrying an electro-magnet with a circuit for the same, and'a hatchway door carrying means to engage a locking member, of a casing supported adjacent the path of travel of the electro-magnet, said casing supporting a pivoted locking member part of which lies within the path of travel of the said means on the door, and a movable releasing member of magnetic material supported by the casing and adapted in one of its positions to hold the locking member in a locked position, and, when actuated by the electromagnet, to release the said locking member.

20. The subject-matterof claim 19 wherein the said locking member has part thereof fashioned to form lips adapted to be engaged bv the said means on thedoor.

21. The subject-matter of claim 19 wherein said releasing member consists of a movable metallic plate located adjacent the path of travel of the electro-magnet on the elevator car.

22. The subject-matter of claim 19 wherein the said locking member and said releasing member are pivoted to the casing in different planes.

23. The subject-matter of claim 19 with the addition of means on the casing to limit the movements of the locking member in opposite directions.

24. The subject-matter "of claim 19 with the addition of means for interlocking the locking member and the releasing member.

25. The subject-matter of claim 19 wherein said locking member has a projection on the same adapted to engage said releasing member in one of its positions and interlock therewith.

26. The subject-matter of claim 19 with the addition of spring means to force the releasing member into interlocking relation with the locking member.

27. The subject-matter of claim 19 wherein the said releasing member consists of a metallic plate pivoted adjacent one edge to said casing.

28. The subject-matter of claim 19 wherein said locking member and releasing memberare pivotally supported within the easing, the releasing member being located adjacent the path of travel of the electro-magnet on the car.

29. The subject-matter of claim 19 with the addition of parts of a main car controlling electric circuit located and spaced apart within said casing forming with one o t the movable elements a switch which is closed when the saidlocking member is in a locked position and open when said locking member is moved from said locked position.

30. The combination in a safety locking apparatus for elevator doors, of a hatchway door carrying door-holding means adapted ing means and door, and an element of mag netic material constituting an armature acting normally to hold the movable door-locking element in locking position, said element of magnetic material being located adjacent -when the said door is opened and closed.

32. The combination of an elevator car, an electro-magnet carried by the car, an electrical circuit for the electro-magnet, a switch for said circuit, a plate of magnetic material, means as a casing or frame supporting said plate adjacent the path of travel of the electro-magnet on the car, saidplate being movable relative to the casing or frame and the electro-magnet, spring means normally forcing said plate away from the path of travel of the electro-magnet, a hatchway' door, door-holding means on the door, and movable means supported by the casing or frame and interlocking with said plate adapted normally toengage said means on the door and hold the door locked, said electro-magnet when energized and brought to a position opposite said. plate moving said plate against the action of the said spring means and releasing the door so it can be opened.

33. The combination in a safety locking apparatus for elevator doors, of a hatchway door carrying door-holding means adapted to be engaged by a locking element; an elevator car; an electro-magnet carried by the car; an electric circuit for the electro-mag net adapted to be connected with a suitable source of electrical energy; a switch for controlling the circuit; and a lock comprising a movable door-locking element adapted to engage said door-holding means and normally lock the door, an element of magnetic material constituting an armature and means actuating said element of magnetic material in one direction normally to hold said door-locking element in locking position said element of magnetic material being movable within limits, when actuated by the electromagnet carried by the car, and in opposition to said means or movably actuating the same in one direction, to release the doorlocking element.

34. The subject-matter of claim 33 with the addition of an electric control circuit adapted for connection with an electric motor for operating the car, said circuit being closed by the said door-locking element when the hatchway door is locked and opened when the said door is opened. Y

35. The subject-matter of claim 33 with the addition of spring means for actuating the said element of magnetic material to hold said door-locking element in looking position, said element of magnetic material being moved when actuated by the electro-magnet against the energy exerted by the said spring means.

36. The combination with an elevator car and a hat-chway door carrying a door-holding member, of a casing with locking means for said door-holdin'g member said means including a movable element of magnetic material, a main operating electric circuit for the car said circuit connecting with the cas ing and adapted to be closed when the door is closed and opened when the door is opened, i

an electro-magnet carried by the car, a circuit for said electro-magnet, and a switch for the circuit said element of magnetic material being located adjacent the path of the travel of the electro-magnet on the car and when moved from its locking position by the electro-inagnet releasing the door-holding member so the door can be opened.

37. The combination with an elevator car and a hatchway door carrying door-holding means, of a casing supporting door-locking means for said door-holding means including an element of relatively high magnetic material, an electro-magnet carried by the car, an electric circuit for said electro-magnet, and a switch; said casing being supportedadjacent the path of travel of the electro-magnet on the car, and'the side of the casing adiacent said path of travel being of relatively low or non-magnetic material.

38. The combination of an elevator car, an electro-magnet carried by the car, an electrical circuit for the electro-magnet, a hatchway door carrying holding means; a casing and door lock supported adjacent the path of travel of the electro-magnet on the car. and.

DON ALONZO SANFORD. 

